CN220754346U

CN220754346U - Inverter tripping self-test circuit

Info

Publication number: CN220754346U
Application number: CN202322272387.3U
Authority: CN
Inventors: 张军军
Original assignee: Linyuan Power Nanjing Co ltd
Current assignee: Linyuan Power Nanjing Co ltd
Priority date: 2023-08-22
Filing date: 2023-08-22
Publication date: 2024-04-09
Anticipated expiration: 2033-08-22

Abstract

The utility model provides an inverter tripping self-test circuit, which comprises a power generation group for outputting alternating current, wherein the power generation group is connected with a box transformer for boosting, the power generation group comprises inverters directly connected with the box transformer, the inverters are respectively and electrically connected with a plurality of branches for outputting direct current, and the branches comprise a plurality of power generation plates connected in series; an insulation detector is arranged between the inverter and the box transformer, the insulation detector is used for monitoring whether a power generation group has a ground fault or not, the output end of the insulation detector is electrically connected with a fault locator, the fault locator is electrically connected with a plurality of low-frequency current transformers, each branch is provided with a low-frequency current transformer, and the fault locator is in data intercommunication with a host. The utility model can directly determine the branch circuit generating the ground fault, improves the maintenance efficiency of staff, and improves the generated energy by shortening the power-off time of the inverter.

Description

Inverter tripping self-test circuit

Technical Field

The utility model relates to the technical field of ground fault detection, in particular to an inverter tripping self-test circuit.

Background

In the photovoltaic power generation field, a plurality of photovoltaic panels are connected in series and then used as a branch to be connected with an inverter. The inverter may convert the direct current generated by the photovoltaic panel into alternating current, which is then fed into the box transformer. After the box transformer is boosted, electric energy is collected into the power plant, and after the power plant is boosted for the second time, the electric energy is transmitted out. Each inverter is connected with a plurality of branches in parallel, if the inverter trips and the inverter is judged to have no problem, whether a grounding condition exists on a connecting line of each branch and the inverter or not needs to be checked, and if the grounding condition exists, the grounding condition needs to be eliminated in time. During inspection, operation and maintenance personnel need to disconnect the connection between the inverters, then carry out one-to-one investigation connecting wire insulation problem according to operation and maintenance manual standard, even sometimes need to draw out the whole connecting wire to inspect, need spend a large amount of time to detect the connecting wire, greatly reduced manual investigation's efficiency. In the process of checking and replacing the branch, the inverter and the photovoltaic panel are in a disconnected state, and the generated energy of the photovoltaic power generation system is influenced.

Disclosure of Invention

In view of the above, the present utility model provides an inverter tripping self-test circuit, which can directly determine a branch circuit generating a ground fault, improve the maintenance efficiency of staff, and improve the power generation amount by shortening the power-off time of the inverter.

In order to solve the technical problems, the utility model adopts the following technical scheme:

an inverter tripping self-test circuit comprises a power generation group for outputting alternating current, wherein the power generation group is connected with a box transformer for boosting, the power generation group comprises an inverter directly connected with the box transformer, the inverter is respectively and electrically connected with a plurality of branches for outputting direct current, and the branches comprise a plurality of power generation plates connected in series;

an insulation detector is arranged between the inverter and the box transformer, the insulation detector is used for monitoring whether a power generation group has a ground fault or not, the output end of the insulation detector is electrically connected with a fault locator, the fault locator is electrically connected with a plurality of low-frequency current transformers, each branch is provided with a low-frequency current transformer, and the fault locator is in data intercommunication with a host.

Further, a communication module is arranged on the inverter, and the fault locator is in data intercommunication with the host computer through the communication module.

Further, the box transformer substation is electrically connected with a plurality of generating sets respectively, and the insulation detector detects whether a plurality of generating sets have a ground fault simultaneously.

Further, each inverter corresponds to a fault locator, the fault locators are in data intercommunication with the communication modules of the corresponding inverters, and the host is in data intercommunication with the communication modules of the inverters respectively, so that the host can distinguish different inverters.

Further, the host computer is in data communication with the display screen.

Further, a relay switch is connected in series between the power generation group and the box transformer substation, and the output end of the host is correspondingly connected with a control relay.

Further, the type of the insulation detector is IFLS-600.

Further, the number of branches in the power generation group is more than 12.

The utility model has the advantages and positive effects that:

through setting up insulation detector, fault location appearance and install the low frequency current transformer on every branch road, when insulation detector detects that the generating set has the earth fault, insulation detector control fault location appearance action through receiving the data of all low frequency current transformers, judges the branch road that breaks down to with branch road information transmission to the host computer, can directly confirm the branch road that produces earth fault, improve staff's maintenance efficiency, because shorten dc-to-ac converter outage time, can improve the generated energy.

The insulation detector is connected with a plurality of fault locating instruments respectively, each fault locating instrument corresponds to one power generation group, the ground fault condition of the branch circuits in the plurality of power generation groups is monitored and located by using one insulation detector, and the cost is saved while the monitoring accuracy is ensured.

Drawings

The accompanying drawings are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate the utility model and together with the embodiments of the utility model, serve to explain the utility model. In the drawings:

fig. 1 is an overall block diagram of an inverter trip self-test circuit of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The utility model provides an inverter tripping self-test circuit, which is shown in figure 1 and comprises a box transformer for boosting, wherein the box transformer is connected with a plurality of power generation groups for outputting alternating current, each power generation group comprises an inverter directly connected with the box transformer, the input end of the inverter is respectively and electrically connected with a plurality of branches, and each branch comprises a plurality of solar panels connected in series. The branch circuit is used for outputting direct current, the inverter is used for converting the direct current into alternating current, and the box transformer is used for boosting the alternating current.

In order to simultaneously monitor whether all the generating sets generate the ground faults, an insulation detector is arranged between the box transformer substation and the generating sets, and the insulation detector simultaneously monitors whether all the generating sets generate the ground faults.

The output end of the insulation detector is respectively and electrically connected with a plurality of fault locators, and the fault locators are in one-to-one correspondence with the power generation group so as to determine the branch information of the power generation group with faults. When one generating set has a ground fault, the insulation detector gives control feedback, all fault locators act simultaneously, all branches in the generating set are detected, and the fault locators acquire the branch information of the abnormal branches in the generating set.

Taking a power generation group comprising 12 branches as an example: the fault locator comprises 12 wiring ports, the 12 wiring ports are electrically connected with 12 low-frequency current transformers, and the low-frequency current transformers are respectively arranged on 12 branches.

When the fault locator operates, fault locating currents of the 12 low-frequency current transformers are received respectively and compared with current fault values, and branch information of ground faults is determined.

The inverter is internally provided with a communication module, the fault locator is in data intercommunication with the host computer through the communication module, the host computer is provided with a plurality of data interfaces, and different data interfaces are in data intercommunication with the communication modules of different inverters so as to acquire inverter information. The host receives the branch information through the communication module of the inverter so as to directly acquire the inverter information with the ground fault and the corresponding branch information.

The output end circuit of the host is connected with a display screen which is in data intercommunication with the display screen, and when a ground fault occurs, the display screen is used for displaying the fault inverter information and the corresponding branch information.

The relay switch is connected in series between each inverter (generating set) and the box transformer substation, the output end of the host is respectively and electrically connected with a corresponding control relay, the host controls the corresponding relay switch to be disconnected through the control relay, the connection between the generating set and the box transformer substation is disconnected (when in actual use, after the relay switch is disconnected, the insulation detector continuously monitors whether a ground fault exists or not, and the disconnected generating set can be further determined to actually have the ground fault).

The maintainer reaches the position of the inverter of the fault generating set, disconnects the connection between the fault branch and the inverter, manually closes the relay switch, and the generating set is connected into the generating set box again, so that the normal power generation of other branches is not influenced, and the generated energy is improved.

The service personnel inspect and repair the faulty leg and re-connect the leg to the inverter. The ground fault problem can be monitored fast and accurately, the position of the fault branch can be positioned fast, the fault detection efficiency is improved, and the time for an maintainer to check the fault branch back and forth is reduced.

The foregoing describes the embodiments of the present utility model in detail, but the description is only a preferred embodiment of the present utility model and should not be construed as limiting the scope of the utility model. All equivalent changes and modifications within the scope of the present utility model are intended to be covered by this patent.

Claims

1. The tripping self-test circuit of the inverter is characterized by comprising a power generation group for outputting alternating current, wherein the power generation group is connected with a box transformer for boosting, the power generation group comprises inverters directly connected with the box transformer, the inverters are respectively and electrically connected with a plurality of branches for outputting direct current, and the branches comprise a plurality of power generation plates connected in series;

2. The inverter trip self-test circuit of claim 1, wherein the inverter is provided with a communication module, and the fault locator is in data communication with the host computer through the communication module.

3. The inverter trip self-test circuit according to claim 1, wherein the box transformer is electrically connected with a plurality of power generation groups respectively, and the insulation detector detects whether a plurality of power generation groups have a ground fault at the same time.

4. An inverter trip self-test circuit as defined in claim 3 wherein each of said inverters corresponds to a fault locator, said fault locator being in data communication with the communication module of the corresponding inverter, said host being in data communication with the communication modules of the inverters, respectively, for the host to distinguish between different inverters.

5. The inverter trip self-test circuit of claim 1 wherein said host is in data communication with a display screen.

6. The inverter tripping self-test circuit according to claim 1, wherein a relay switch is connected in series between the power generation group and the box transformer, and the output end of the host is correspondingly connected with a control relay.

7. The inverter trip self-test circuit of claim 1 wherein said insulation detector is of the type IFLS-600.

8. The inverter trip self-test circuit of claim 1 wherein the number of legs in said power generation set is no more than 12.